<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
    <style>
      .a {
        display: flex;
      }
    </style>
  </head>
  <body>
    <div id="app">
      <div v-for="(item,index) in arr" class="a" :key="index">
        <li>{{item}}</li>
        <button @click="dul(index)">删除</button>
      </div>
      <button @click="fn">生成</button>
    </div>

    <script src="./vue.js"></script>
    <script>
      const app = new Vue({
        el: '#app',
        data: {
          arr: [1, 2, 5, 10]
        },
        methods: {
          fn() {
            this.arr.push(Math.floor(Math.random() * 20))
          },
          dul(index) {
            // this.arr.splice(index, 1)
            this.arr = this.arr.filter((item, i) => i !== index)
          }
        }
      })
    </script>
  </body>
</html>
